For starters, babies don’t catch yawns — children start catching yawning around the age of four or five (around the same time they start developing empathy).

In addition, psychopaths and people with autism (a condition associated with lower levels of empathy) are also less likely to catch yawns.

Scientists have also found that the closer you are to someone, the more likely you are to catch their yawn. A recent study found that yawn contagion was highest among family members, then for friends, then for acquaintances and the lowest for strangers.

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Finally, women score higher than men on tests of empathy — and are also known to be more likely to catch yawns.